Air Conditioners leak water for a few reasons. It is possible that the air flow over the indoor evaporator coil is restricted due to either a dirty coil or a dirty air filter. You should change the filters every 3-6 months.  If you are doing any sort of home remodeling, you should check the filters during the renovation because dust and particles can clog up the filters very fast.  In either case this will cause the evaporator coil to ice up and leak water over the edge of the condensate drain pan.

First check for proper installation. The unit should be mounted level or with a slight 1/4″ tilt to the outside. If the unit has not been serviced, it may have plugged water passages and require cleaning from an authorized service provider. Under extreme conditions, a drain kit may need to be installed.  AC units have a drip pan, a main drain that goes to the plumbing system and a secondary drain that is suppose to drip somewhere obvious.  The drain pipes are usually 3/4″ white plastic pvc piping.  They are usually located on the exterior of a house above a door or window, though can sometimes be located on the ceiling about a bathtub.

What causes water to leak from an air conditioner?

The most common reason for the air conditioner to leak water is that the condensate drain line becomes clogged causing the drain pan to overflow. During the hot summer months we get in San Antonio, Texas when the air conditioning unit is working hard, there is a lot of moisture being pulled out of the air in the home.  As this water drips down the evaporator coil and into the drain pan algae and other debris that form and run through the drain line.   If not maintained, this algae and debris will clog the line.  This will  force the water to overflow into the drip pan or trigger a water detection device (float switch) that is connected to the drain that will shut the air conditioner off before it overflows.  Now it is time to call in a professional.  Most air conditioning companies will give free estimates.  Call around and have at least 3 companies diagnose the problem and present you with a solution and a price to fix it.